As explained in Steamship Mutual website article US - Vessels from Ports Not Maintaining Effective Anti-Terrorism Measures the U.S. Coast Guard imposes conditions of entry on vessels arriving to the United States from countries deemed not to be maintaining effective anti-terrorism measures.
With effect from 23 January 2009 Venezuela is the latest addition to the list of such countries and special measures apply to vessels wishing to call at US ports that have also called at Venezuela as one of the last five ports of call.
Further details are available in the article given above and also on the U.S. Coast Guard Homeport Website.
